Taxes - Married filing separately

I learned something new yesterday.  As a common law state, in Wisconsin, married couples can file taxes as married filing separately and choose to each file half of each other's income.  If one party decides to file that way, both parties must file that way.  This means that if one party earns $100,000 a year and the other party earns $10,000 a year, then both parties would claim $55,000 of income on their taxes.  The party only earning $10,000 would likely find it VERY difficult to come up with all the tax that would be due especially if the parties are separated or going through a divorce.  So this is something that really needs to be thought through before court orders specify how the parties will file their taxes.